TiO2-B was synthesized by solid-state reaction. The structures, surface morphologies and electrochemical performances of TiO2-B were characterized by X-ray diffractometry （XRD）, scanning electron microscopy （SEM） ...TiO2-B was synthesized by solid-state reaction. The structures, surface morphologies and electrochemical performances of TiO2-B were characterized by X-ray diffractometry （XRD）, scanning electron microscopy （SEM） and electrochemical measurement, respectively. The effects of calcining temperature, molar ratio of K2O to TiO2 and calcining time on the characteristics of TiO2-B were investigated. The results show that the calcining time exerts a significant influence on the electrochemical performances of TiO2-B. The TiO2-B is obtained with good crystal structure and suitable size by using K2Ti4O9, which is prepared at 950 ℃for 24 h under the condition of x（K2O）/x（TiO2）=1：3.5. The TiO2-B delivers all initial discharge capacity of 231.6 mA.h/g. And the rate caoacitv is 73.2 mA-h/g at 1 675 mA/g, which suggests that TiO2-B is a promising anode material for the lithium ion batteries.展开更多
Developing high-performance lithium ion batteries(LIBs)using manganese oxides as anodes is attractive due to their high theoretical capacity and abundant resources.Herein,we report a facile synthesis of hierarchical s...Developing high-performance lithium ion batteries(LIBs)using manganese oxides as anodes is attractive due to their high theoretical capacity and abundant resources.Herein,we report a facile synthesis of hierarchical spherical MnO2 containing coherent amorphous/crystalline domained by a simple yet effective redox precipitation reaction at room temperature.Further,flower-like CoMn2O4 constructed by single-crystalline spinel nanosheets has been fabricated using MnO2 as precursor.This mild methodology avoids undesired particle aggregation and loss of active surface area in conventional hydrothermal or solid-state processes.Moreover,both MnO2 and CoMn2O4 nanosheets manifest superior lithium-ion storage properties,rendering them promising applications in LIBs and other energy-related fields.展开更多
A 3D nitrogen⁃doped graphene/multi⁃walled carbon nanotube(CS⁃GO⁃NCNT)crosslinked network mate⁃rial was successfully synthesized utilizing chitosan and melamine as carbon and nitrogen sources,concomitant with the incor...A 3D nitrogen⁃doped graphene/multi⁃walled carbon nanotube(CS⁃GO⁃NCNT)crosslinked network mate⁃rial was successfully synthesized utilizing chitosan and melamine as carbon and nitrogen sources,concomitant with the incorporation of multi⁃wall carbon nanotubes and employing freeze drying technology.The material amalgamates the merits of 1D/2D hybrid carbon materials,wherein 1D carbon nanotubes confer robustness and expedited elec⁃tron transport pathways,while 2D graphene sheets facilitate rapid ion migration.Furthermore,the introduction of nitrogen heteroatoms serves to furnish additional active sites for lithium storage.When served as an anode material for lithium⁃ion batteries,the CS⁃GO⁃NCNT electrode delivered a reversible capacity surpassing 500 mAh·g^(-1),mark⁃edly outperforming commercial graphite anodes.Even after 300 cycles at a high current density of 1 A·g^(-1),it remained a reversible capacity of up to 268 mAh·g^(-1).展开更多
基金Project(2007BAE12B01) supported by the National Key Technology R&D Program of China
文摘TiO2-B was synthesized by solid-state reaction. The structures, surface morphologies and electrochemical performances of TiO2-B were characterized by X-ray diffractometry （XRD）, scanning electron microscopy （SEM） and electrochemical measurement, respectively. The effects of calcining temperature, molar ratio of K2O to TiO2 and calcining time on the characteristics of TiO2-B were investigated. The results show that the calcining time exerts a significant influence on the electrochemical performances of TiO2-B. The TiO2-B is obtained with good crystal structure and suitable size by using K2Ti4O9, which is prepared at 950 ℃for 24 h under the condition of x（K2O）/x（TiO2）=1：3.5. The TiO2-B delivers all initial discharge capacity of 231.6 mA.h/g. And the rate caoacitv is 73.2 mA-h/g at 1 675 mA/g, which suggests that TiO2-B is a promising anode material for the lithium ion batteries.
基金Project(JCYJ20170817110251498)supported by the Basic Research Project of the Science and Technology Innovation Commission of Shenzhen,ChinaProject(2016TQ03C919)supported by the Guangdong Special Support for the Science and Technology Leading Young Scientist,ChinaProject(21603094)supported by the National Natural Science Foundation of China
文摘Developing high-performance lithium ion batteries(LIBs)using manganese oxides as anodes is attractive due to their high theoretical capacity and abundant resources.Herein,we report a facile synthesis of hierarchical spherical MnO2 containing coherent amorphous/crystalline domained by a simple yet effective redox precipitation reaction at room temperature.Further,flower-like CoMn2O4 constructed by single-crystalline spinel nanosheets has been fabricated using MnO2 as precursor.This mild methodology avoids undesired particle aggregation and loss of active surface area in conventional hydrothermal or solid-state processes.Moreover,both MnO2 and CoMn2O4 nanosheets manifest superior lithium-ion storage properties,rendering them promising applications in LIBs and other energy-related fields.
文摘A 3D nitrogen⁃doped graphene/multi⁃walled carbon nanotube(CS⁃GO⁃NCNT)crosslinked network mate⁃rial was successfully synthesized utilizing chitosan and melamine as carbon and nitrogen sources,concomitant with the incorporation of multi⁃wall carbon nanotubes and employing freeze drying technology.The material amalgamates the merits of 1D/2D hybrid carbon materials,wherein 1D carbon nanotubes confer robustness and expedited elec⁃tron transport pathways,while 2D graphene sheets facilitate rapid ion migration.Furthermore,the introduction of nitrogen heteroatoms serves to furnish additional active sites for lithium storage.When served as an anode material for lithium⁃ion batteries,the CS⁃GO⁃NCNT electrode delivered a reversible capacity surpassing 500 mAh·g^(-1),mark⁃edly outperforming commercial graphite anodes.Even after 300 cycles at a high current density of 1 A·g^(-1),it remained a reversible capacity of up to 268 mAh·g^(-1).
